Apparatus for treatment with solvents



April 7,, 1936.. c. F. DINLEY Y APPARATUS FOR TREATMENT WITH SOLVENTSFiled Oct. 1 1932 6 Sheets-Sheet l.

- INVENIOR:

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ATTORNEYS.

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Aprll 7, 1936. c. F. IDIINLEY APPARATUS FOR TREATMENT WITH SOLVENTS 7Filed 'Oct. 1, 1952 6 Sheets-Shem 2 INVENTQR: ammmfi flmwy, BY MugATTORNEYS.

'WITNESSES:

April 7, 1936.. c. F. DINLEY APPARATUS FOR TREATMENT WITH SOLVENTS 6Sheet s-Sheet 3 Filed 00 l, 1952 April 7, 1936., c; DINLEY 2,3 21

APPARATUS FOR TREATMENT WITH SOLVENTS Filed Oct. 1, 1932 6 Sheets-Sheet4 H J2 H fl I INVENTQRQ zymvssszzs. M (510mg mnwy,

ATTORNEYS.

Aprfl 7, 1936.,

c. F.DINLEY 2,036,261 APPARATUS FOR TREATMENT WITH SOLVENTS Filed 001;.l, 1952 1 6 Sheets-Sheet 5 F]G W W] TNESSES: INVENTR:

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c. F. DINLEY APPARATUS FOR TREATMENT WITH SOLVENTS Sheets-Sheet 6 FiledOCt. l, 1932 INVENTIOR; @mmma Wpmm BY Q ATTORNEYS.

FIG

Patented Apr. 7', 1936 UNITED STATES APPARATUS lgOR TREATMENT WITHOLVENT Clarence r. Dlnley, Detroit, men, asslgnor James H. Bell,Philadelphia, Pa.

Application October I, i932, Serial No. ddhldt 12 Claims.

My invention relates to treatment with solvents for such purposes ascleaning and degreasing, etc, and particularly to the use of volatilesolvents; especially solvents whose vapors are heavier than air, such asbenzine, benzol, and chlorinated solvents like carbon tetra chloride andtrichlorethylene, whose vapors are uninfiammable. My invention aims toprovide a compact, convenient and eflicient apparatus for this purpose,which though very simple' (and easily operated by a single unskilledoperator) will satislactorily clean a great deal of work for thecleaning of which a large commercial demand exists. How these and otheradvantages can be realized through the invention will appear from mydescription hereinafter of several preferred forms of embodiment.

In the drawings, Fig. I is in a r r a side elevation and in part avertical section of one form of apparatus convenient for my purpose.

Fig. II is a side elevation at right angles to Fig. I.

Fig. III is a plan view of the apparatus, with a broken away.

Fig. IV shows a cross-section of a basket container for the work to betreated, on a larger scale than Fig. I; and

Fig. V is a corresponding fragmentary side view of one end of thiscontainer.

Flg.'VI is a side view, similar to Fig. I, illustrating a somewhatdifferent form of apparatus.

Fig. VIII is a fragmentary end ,view, showing the upper portion of theapparatus of Fig. VI.

Fig. VIII is a side view, similar to Figs. I and VI, illustrating yetanother form of apparatus; and

Fig. IX is a side or end elevation at right angles to Fig. VIII, but ona somewhat larger scale, a portion being broken out to bring'the heightof the apparatus within the limits of the paper.

The several different forms of treating apparatus-shown in the drawingsall embody certain common features, as will appear from comparison ofFigs. I, VI and VIII; viz.: They have a treating vessel or tank 8 thatserves to exclude wells are provided by partitioning (l6, lfia, ISA)that permits liquid solvent to accumulate in one of the wells above itslevel in another, and to overflow over the partitioning from the onewelt (@l. hit-d) to the other, as over a dam. (In Fig. ill there arepipe and valve connections ltb, the as an alternative means ofoverflow.) y heating means (24, 24a, 24A) associated with a well (M, Ma,or ii) receiving such overflow, liquid solvent therein may be heated andvaporized, while the overflowing well may be left cooler. Though thetreating wells are open upward and readily accessible from above, yetsolvent vapor arising from any of them is retained by suitable extensionof the walls of vessel 8 upward above the wells, and by condensing thevapor from. this upper part oi the vessel, which is (externally) waterjacketed at 29 for this purpose. The thus distilled and purified solventis normally supplied to the cooler well above referred to, to accumulatetherein and overflow into the heated or vaporizing well. To iacilitateclean of the apparatus when necessary, a storage reservoir (it, lda,ltd) is shown, to receive the distilled solvent, and also suitableprovisions for transferring, returning, or draining liquid solvent fromother parts of the apparatus to the vapor well.

As here she, the apparatus comprises a treating vessel or enclosure inthe form of a rectangular sheet metal tank d with bottom d slop-= ingsomewhat from either side or end toward the center. The tank 8 issupported by a tramswork of angle uprights or legs in at its corners,with their upper ends engaged under a rectangu lar frame oi channels ll,it about the open top or mouth of the tank. The ends of the side channels ii are shown projecting beyond the tank d and braced thereto bybraces lie. at or around the bottom corners of the tank is a horizontalframing of structural members it, with their ends secured in the anglesof the legs it, which are brd thereto (and to the tank) by (gussetplate) braces it. In the lower portion of the tank t are separatetreating spaces or wells ll, it for treatment of the work with solvent,sep arated-by a (hollow) vertical sheet metal parti tion or darn it. Thebottom of the well it is formed by the sloping t bottom d; that of thewell it by a sloping sheet metal wall l'l, considerably above the bottom9. The space heneath the bottom ill and inside the dam it affords aclosed storage reservoir lb of sumcient'capacity to hold all the solventin the apparatus. As here shown, there is a drainage pipe connection l9from the bottom of the well it into the tank 118 controlled by a valve2d, and there is also a suction pipe connection it from the bottom 01:the tank l8 to a (crank-operated) hand pumpjl:

(such as a gear pump) that delivers through a pipe 23 dischargingthrough the side of the tank 3 into the well i4, preferably above the.top of the dam it-all for a purpose explained hereinafter. Solvent inthe well l4 may be heated (and vaporized) by any suitable heating means,such as a steam jacket 24 on its bottom-shown as having inlet and outletpipe connections 25, 28 at its diagonally opposite upper and lowercorners. The wall II has a drainage outlet connection 21 at one of itslower corners, controlled by a valve 28.

Around the upper portion of the tank. 8, above the well i5, is acold-water-jacket condenser, shown as engaging subjacent external angles29a on the tank sides: it has inlet and outlet connections 29b, 290 atthe opposite tank sides, the former at the jacket bottom and the latterat its top. In the present instance, the condenser 29 is U-shaped inplan (Fig. III), extending across one end of the tank 8 and part wayalong the adjacent tank sides. The vapor evolved from the heated solventin the well 14 accumulates and fills the tank 8 about to the mid-levelof the condenser 29. Condensed by the condenser 29, the solvent dripsand runs down into the well i5, which is thus supplied with the purifiedcondensate, and kept full and comparatively cool. The excess overflowsover the top of the partition i6 into the well M, where it is vaporized,etc., indefinitely. As shown in Fig. I, the top of the partition or damto slopes rather gently upward, in the direction of overflow, to itscrest, to facilitate overflow of drops of water floating at the surfaceof the solvent in well l5. Such drops of water float partly submerged inthe solvent in well l5,- something like ice-bergs--and the comparativelygentle slope of the top of the dam i5 allowsthe overflowing solvent toroll these waterdrops up" the slope and over the crest of the dam. Butfor this, water condensing from the superjacent air in contact with thevapor in the vessel 8 would accumulate into a layer covering the top ofthe liquid solvent in the well l5, and this water layer would tend towaterspot the work treated in the well I5.

The things or work to be treated are first washed by immersion in the(boiling) hot solvent in the well i l, and then transferred to the welll5 and rinsed by immersion in the (cooler) purified solvent therein. Thework may then be raised into the atmosphere of solvent vapor above thetop of the dam l6, and kept there awhile to be further cleansed bysweating with pure solvent condensing on its surfacesince its immersionin the rinse bath at l5 has cooled the work below the boiling point ofthe solvent. When such sweating ceases (owing to gradual heating up ofthe work to the temperature of the vapor), the work may be removed.

For handling or manipulating the work as just described, mechanism isshown for raising and lowering it and shifting it horizontally,comprising a carriage 30 movable back and forth across or adjacent theopen top of the tank 8, and carrying an overhead supporting structure orcrane 3|. There is also a foraminous container or basket 32 for thework, attached to a flexible cable 33 extending up over a pulley 34 onthe crane St. to a winding drum 35 thereon. As shown in Fig. 11, thecarriage 30 has a horizontal open rectangular frame provided withbearing brackets 37 on which are mounted rollers 38 that run in guideways afforded by the side channels I I of the tank mouth frame alreadymentioned. The crane 3! has an upright 40 attached to one side of thecarriage frame 30 (and braced thereto by a gusset plate 4i),and'extending both above and below the carriage, and a horizontal headmember 42 projecting forward over the tank 8 and ca y bearings 43, 44for mounting the pulley 34 and drum 3!. The shaft 45 of the drum 3! isshown mounted directly in the head bearings 44. However, the pulley 34is not mounted directly on the head 42, but on the forward end of a rocklever 43 itself fulcrumed or pivoted in the head member 42. Foroperating the drum 3!, there may be provided a hand-crank-wheel 41 whoseshaft 48 (mounted in bearing brackets 48 projecting rearward from thelower end of the upright 40) may be connected to the shaft 45 of thedrum 35 through a shaft (mounted in bearings on the brackets 49)worm-geared to the shaft 48, and a sprocket chain connection 5| fromsaid shaft 50 to the drum shaft 45. For keeping the sprocket chain 5itaut there is shown an idle sprocket 52 adjustable sidewise of the chainin brackets 53 on the crane upright 40. As shown, the hand-wheel shaft58 carries a crank 54 that is connected by a link-rod 55 to the rear endof the rocker 46 that carries the pulley 34; so that as the drum 35 isturned, the pulley M is vibrated up and down, and so likewise the workin the basket 32.

As shown in Figs. 1, II, IV and V, the basket 32 has the form ofpolygonal (octagonal) prism, and has angle-bar (basal) end framesconnected at their corners by angle bar longitudinals 6 l A U-shapedlifting bail 62 is bolted to the end frames to at 63, and the cable 33is attached to its middle, as by a bolt 64. The basket 32 (see Figs.

IV and V) has a top opening, for receiving the work, that is normallyclosed by a cover 55 hinged at 66 to one of the longitudinals BI, and abottom opening for discharging the work, normally closed by a, dumpbottom 61 hinged at 58 to one of the longitudinals 6i and held shut byone or more catches 69. As shown in Figs. IV and V, the top and bottomopenings are each substantially coextensive with two adjacent sides ofthe basket prism, whose longitudinal corner members (6!) that wouldotherwise span the openings are omitted. The cover is outlined by aframe of flat bars ill, and has an intermediate (angle-bar) longitudinalii at the prism corner, in lieu of the omitted main frame member 6|. Thecover 65 may also have a sheet metal frame 12 welded over its frame 10on the outside, and projecting beyond the latter to afford a flange orrabbet for seating on the main frame members 60, 6| around the topopening. The bottom 61 may be of similar construction, as indicated bylike reference numerals applied to its various parts. The bottom catches69 are shown in Fig. V as comprising angle levers pivoted on a framemember 6| at 13 and having catch arms 14 for engaging in notched clips15 secured to the bottom 61, as well as handles for convenientoperation. The end and side panel openings of the main frame and of thecorner and bottom frames are covered with foraminous metal (such aswoven wire) 15 welded against the inner surfaces of the framing, so asto retain even very small articles while affording the solvent (and itsvapor) free access to the articles.

A mode of operation of the apparatus is as follows: Y

Initially, the well I4 is charged with liquid solvent to the fillinglevel" indicated by the dot and dash line L. Steam is supplied andpassed through the jacket 24, and condensing water through the condenser29. Thus the solvent in the well I4 is boiled and distilled over intothe well I 5, and the latter filled to overflowing at the level of thedot and dash line L; while the solvent in the well i4 is reduced to thenormal operating level indicated by the dot and dash line I.

With the parts in their full-line positions (A) of Fig. I, the bottom 61of the basket 32 is closed and secured by its catch 69, and a batch ofthe articles or work to be treated is placed in the basket, and itscover 65 also closed. The hand wheel M is operated to rotate the drum 35and thus lift the basket 32 above the top of the tank 8; and then thecarriage 30 is pushed to the right (Fig. I) to the dot anddash position,and the hand wheel 41 is reversely operated to lower the basket 32 intothe boiling hot solvent bath at it.-

As the basket 32 descends, the crank 54 oscillates the rocker 46 up anddown, thus vibrating or joggling the basket 32 up and down in thesolvent, and tumbling and agitating its contents in the solvent toassure thorough contact of the latter with all surfaces of everyarticle. When the basket bl reaches its dot and dash line position (E)of total immersion in bath M, it may be left stationary awhile, and theagitation of the solvent by boiling may be relied on to tumble thearticles and assure thorough access of the solvent to all theirsurfaces; or the hand wheel ll may be oscillated by hand sufficiently tojiggle the basket up and down without raising or lowering it materially.

When the work has thus been washed in the bath it as much as desired,the handwheel tl may be operated to lift the basket 32 above the top ofthe darn it, and the carriage Iili may be pushed further to the right;whereupon the handwheel M may be operated to lower the hasket into thecooler, purer solvent bath at it, with concurrent up and down jigglingas before. The basket it may be left stationary in the dot and dashposition of total immersion in bath lb; or it may be jiggled up and downtherein to rinse the work more efiectively, as in the bath id.

When the work has thus been rinsed and cooled as much as desired, thehandwheel tl is operated'to lift the basket 32 out of bath iii (andabove the top of the dam it). into the vapor in the upper portion of thetank 8. Preferably, the carriage it is also pushed to the left to bringthe basket it above its position (B), and the basket lowered somewhat(though not to the point of even partial immersion) to plunge the workmore deeply in the upward stream of solvent vapor from the bath it. Herethe work is further cleaned by pure solvent condensing on its relativelycool surface.

When the work has heated up to the vapor temperature, or the vaportreatment has continued as long as desired. the handwheel ll is ooeratedto lift the basket 32 above the top of the tank t; the carriage iii ispushed further to the left; and the handwheel 41 is operated to lowerthe basket 32 back to its initial position (A).

Thereupon the bottom 61 is released and the work v dumped or dropped outof the basket; whereupon the bottom 61 may be closed and secured by itscatches t9, and the cover 65 opened-ready for .a repetition of the cyclewith a fresh batch of work. I i

It will be understood, of course, that the cycle of operation describedis illustrative. and can be greatly varied in practice: e. g., for roughcleantreatment may start in the bath l-with or without subsequent vaportreatment, according to the thoroughness of cleansing desired.

When the solvent in baths l4 and I5 has become so contaminated with dirtand grease that further satisfactory cleaning therewith is impossible,it may be purified in the apparatus as follows:

The supplies of steam and water to jackets 24 and 29 continuing, valve20 is opened and the solvent in well I5 is drained into the storagereservoir l8, whereupon the well it may (if necessary) be cleaned. Thepump it is operated to pump the solvent from reservoir it into well it,which then contains all the solvent in the apparatus. The solvent isboiled in well it and all distilled over into 'well it. Thereupon steammay be shut oif (if desired) from jacket it and well it thoroughlycleaned. Then pump it is used to return all the solvent to welllit-after (or before) which valve it is closed, and steam (if previouslyshut off) is turned on again into jacket 2t. As soon as suflicientsolvent has distilled over into well it, the apparatus is ready v hasdistilled over and drained into reservoir ll;

whereupon steam may be shut 0d, well it cleaned, all solvent pumped fromreservoir it into well it, valve 2b closed, and steam turned on again.

The apparatus shown in Figs. VI and VII is of 1 double the depth andcapacity as in Fig. l. The

heater for the solvent in the well Mia is shown as a horizontalserpentine steam pipe l lo mounted on a removable cover ltb secured overan opening in the side of the tank to. The storage reservoir tank its;for cleaning purposes is located alongside the rinsing well liia.instead of beneath it as in Fig. I, though it extends down belowthebottom of the well llba to afford ample capacity. From the top of thetank lta there is an air vent pipe ltb controlled by a valve the to keepit from becoming airbound against inflow of solvent. The normal liquidlevel in the rinsing well the may be determined by overflow through apipe l6b equipped with a control valve ltc, rather than by overflow overthe dam lta.

The suction connection ll of the hand pump it has separate branches 2m,lib to the well its and to the reservoir its, respectively controlled byvalves i201, lib, respectively. Benea h the level of the (external)horizontal U-condenser it is an internal U-trough 30a formed by aU-section secured (welded) to the tank sides, and sloping toward the endwall of the tank t above the reversely sloping top l dd of the reservoirtank lfla. Ordinarily, condensed solvent accumulating in the trough 38aoverflows from the (horizontal) portion 33b of the trough 33a on the endwall of the tank 8a and runs off the sloping reservoir top I80; into therinsing well a, which is thus replenished with pure, clean, relativelycool solvent. The extension of the conall densing water jacket 29 overor around the top of the reservoir tank I8a affords more amplecondensing surface. Solvent from the trough 30a can also (alternatively)be drained into the reservoir I8a when desired, by means of a connectionI9a controlled by a valve 20a.

The tank 80. is shown provided with half-covers H, H hinged at h, h tothe top angles I Ia, IIa on its longitudinal sides (Fig. VII) these maybe closed to exclude air and obviate or minimize loss of solvent whenthe latter is being boiled for purification.

Various parts and features are marked on Figs. VI and VII with the samereference characters as in Figs. I-III, as a means of dispensing withrepetitive description, and various accessories shown in Fig. I areomitted from Fig. VI. The operation is substantially the same asdescribed in connection with Figs. I-III: but the following points maybe particularly noted.

Ordinarily, solvent overflows from the rinse well I5a into the well I4athrough the pipe IBb, as already mentioned; but when work is to berinsed in the well I So, the valve lie is temporarily closed, so as toprevent solvent equal to the displacement oi the work from overflowingat l6b, which might leave too little solvent in the well I So toproperly rinse the next piece oi. work. When it is desired to clean theapparatus, the covers H, H are closed, the valve 22b is closed, thevalves 22a, 20a (and I) are opened, and all the solvent is pumped fromthe well I5a into the well Ma; and thus it is vaporized and alldistilled over into the reservoir I81; and well I5a,- if the latter berequired to hold part of it. Then the steam is shut off from the coils24a, and the covers H, H are opened and the well I 4a cleaned out. Afterthis, the valves 20a, 22a are closed and the valve 22b opened, and thepurified solvent is all pumped back into'the well I4a, ready forresumption of operation.

The form of apparatus shown in Figs. VIII and IX differs from that ofFigs. I-III principally in the provision of an additional treatingchamber or well ISA, which may be used for an additional, final liquidrinse, or, preferably, for vapor treatment, and may also serve as astorage reservoir (like I8 in Figs. 1411) for cleaning the solvent inthe apparatus when contaminated with dirt and grease. Various parts andfeatures of this apparatus are marked with the same reference charactersas the corresponding ones in Figs, I-III, as a means of dispensing withrepetitive description. It will also be understood that variousaccessories shown in Figs. I-III are omitted for greater clearness ofillustration of more distinctive features, including the carriage 30,crane 3|, etc., etc.

As here shown, the vapor treating well ISA is separated from the rinsingwell I5 by a partition or dam IBA similar to the dam I6, but not sohigh, so that the overflow from well I5 is over this dam ISA into thewell ISA, instead of over dam I6 into well I4. Liquid solvent thusoverflowing into well ISA drains back into well I4 through a pipe ISAcontrolled by a valve 20A, as well as solvent dripping or running downfrom the condenser 29 directly into well ISA. The suction pipe 2IA ofthe pump 22 draws directly from the bottom of rinse well I5, and iscontrolled by a valve 2IB. The steam jacket 24A for heating solvent inwell I4 extends up one side wall of the latter, as well as over itsbottom 9, and the steam supply or inlet connection 25A is into the upperend of this vertical portion of the jacket 24A. The sides of the tank 8Aare shown provided with V-sockets 80 for cross-rods 8| from whichwork-supporting racks 82 may be suspended by their hooks 83-4. e., whenthe carriage 30, crane 3|, etc., etc., of Figs. I-V is not used.

This apparatus is especially well adapted for, cleaning metal work thatis to be electro-plated;

and when it is used for this purpose, the racks 82 may bebakelite-insulated plating racks, which may be transferred with the workdirectly from this cleaning apparatus to the plating bath.

In operation, vapor from the bath I4 fills the chamber ISA, as well asthe interval above it up to the level determined by the condenser 29.Work may go first into the washing bath I4; then into the rinse bath I5;and then into the vapor the solvent in the apparatus is nowin well I4.

This solvent in well I4 is then boiled and distilled over into wells I5and ISA, until well I4 is empty. Well I4 is cleaned (after shutting offthe steam, if necessary); whereupon valve 20A is opened and the solventin well I5A is drained back into well I 4, filling it to the normalworking level I. In this solvent-cleaning cycle, well I5a corresponds tothe reservoir I8 of Figs. I-III. The

apparatus is now ready for resumption of operations, as soon as thesteam (it shut oiI) is turned on again.

The apparatus shown in Figs. VIII and IX offers certain advantages overthat of Figs. I-III, VI and VII: e. g., the progress of work through theapparatus is only in one direction, without need for any return fromrinse bath I5 or vapor bath I5A back over washing bath I4, so that threeracks orbatches of work may be in the apparatus at once without causingany diillculty or complications in operation. The apparatus need not beso deep vertically as that of Figs. I-III to provide for convenientvapor cleaning. The stages to be employed and the needful duration ofeach stage depend entirely on the nature of the work to be dealt with:especially the final vapor treatment, whose proper and possible durationdepends on the mass of the work, since'this influences the length oftime in which it will heat up to the vapor temperature.

Having thus described my invention, I claim:

1. Apparatus of the character described, for treating things or worktherein with volatile solvent whose vapor is heavier than air,comprising an air-excluding treating vessel open upward for introductionand removal of work, and provided with means afi'ording separate solventwells in said vessel and providing for accumulation of liquid solvent inone of said wells higher than the solvent level in another and overflowof excess from the one well into the other and also affording asolvent-vapor-treating well in said vessel draining into one of theaforesaid wells, each of said wells being adapted to receive the work,and also provided with means above said wells for retaining andcondensing solvent va or evolved in the vessel, and for therebysupplying said overflowing well with liquid solvent.

2. Apparatus of the character described, for

. treating things or work therein with volatile sol- ,vent whose vaporis heavier than air, comprising an air-excluding treating vessel openu'pward for introduction and removal of work, and provided with meansaffording solvent wells in said vessel, one higher than another, andalso affording a solvent-vapor-treating well in said vessel drain- 'inginto the lower of the aforesaid wells and receiving overflow fromthe'aforesaid higher well, each of said wells being adapted to receivethe work, and also provided with means above said wells for retainingand condensing solvent vapor evolved in the vessel and for therebysupplying said overflowing well with liquid solvent, and means forheating and vaporizing liquid solvent in the well into which saidvapor-treating well drains as aforesaid.

3. Apparatus of the, character describedfor treating thingsor worktherein with volatile solvent whose vapor is heavier than air,comprising an air-excluding treating vessel open upward for introductionand removal of work, and provided with means aflording separate solventwells in said vessel and providing for accumulation of liquid solvent inone of said wells higher than the solvent level in another and overflowof excess from the one well into the other, and also afford-' sel andfor thereby supplying said overflowing well i with liquid solvent, andwith means for pumping solvent from said overflowing well into saidother well.

, t. Apparatus of the character described, for treating things or worktherein with volatile solvent whose vapor is heavier than air,comprising an air-excluding treating vessel open upward for introductionand removal of work, and provided with means affording separate solventwells in said vessel and providing for accumulation of liquid solvent inone of said wells higher than the solvent level in another and overflowof er.-

cess from the one well into the other, each of said wells being pted toreceive the work, and also provided with means above said wells forretaining and condensing solvent vapor evolved in the vessel and thuspreventing its overflow from the apparatus, and for thereby supplyingsaid overflowing well with liquid solvent, and means for heating andvaporizing liquid solvent in the well receiving the overflow asaforesaid while leaving the overflowing well cooler, thus tending toobviate evaporation of solvent from the overflowing well and so promoteflow of solvent vapor from the other well upward and toward theoverflowing well.

5; Apparatus of the character described, for treating things or worktherein with volatile solvent whose vapor is heavier than air,comprising an air-excluding treating vessel open upward for introductionand removal of work, and

. provided with meansaflording separate solvent ing well with liquidsolvent; a storage reservoir for also receiving liquid solvent thusdistilled, so

that the contents of said well receiving the overflow as aforesaid maybe distilled down to permit of its being cleaned out while the excess ofpurified distillate is meanwhile held in said storage reservoir; andmeans for returning liquid solvent from said storage reservoir to saidother well.

6. Apparatus of the character described, for treating things or worktherein with volatile sol vent whose vapor is heavier than air,comprising an air-excluding treating vessel open upward for introductionand removal of work, and pro tilled liquid solvent to be received insaid higher well; means for heating and vaporizing liquid solvent in thelower well, while leaving the higher well cooler, and a storagereservoir for also receiving the purified liquid solvent distilled fromsaid lower well by the operation of said heating and condensing means,so that the contents of said lower well may be distilled down to permitof its being cleaned out while the resultant purified distillate ismeanwhile held in said higher well and said reservoir; and means forreturning this purified liquid solvent from the higher well and fromsaid reservoir to the vaporizing well.

7. Apparatus of the character descri, for treating things or worktherein with volatile solvent whose vapor is heavier than air,comprising an air-exclu' treating vessel open upward for introductionand removal of work, d provided with means aflording separate solventcontainers or wells in said vessel, one higher than another and normallydischarging thereinto, each of said wells being adapted to receive thework, and also provided with means above said wells for retaining andcondensing solvent vapor evolved in the vessel and thus preventing itstill overflow from the apparatus; a storage container treating things orwork therein with volatile solvent whose vapor is heavier than air,comprising an air-excluding treating vessel open upward for introductionand removal of work, and provided with means affording separate solventwells in said vessel and providing for accumulation of liquid solvent inone of said wells higher than the solvent level in another and overflowof excess from the one well into the other, each of said-wells beingadapted to receive the work, and also provided with means above saidwells for retaining and condensing solvent vapor arising from any ofthem and thus preventing its overflow from the apparatus, and forthereby supplying the overflowing well with purified liquid solvent; astoragereservoir for also receiving the condensed and purified liquidsolvent, so that the contents of said well receiving the overflow asaforesaid may be distilled down to pertil d ll

mit of its being cleaned out while the excess of purified distillate ismeanwhile held in said storage reservoir; and means for pumping upliquid solvent from either said overflowing well or said storagereservoir over into the other well.

9. Apparatus of the character described, for treating things or worktherein with volatile solvent whose vapor is heavier than air,comprising an air-excluding treating vessel open upward for introductionand removal of work, and provided with means aflfording separate solventwells in said vessel and providing for accumulation of liquid solvent inone of said wells higher than the solvent level in another and overflowof excess from the one well into the other, each of said wells beingadapted to receive the work, and also provided with means above saidwells for retaining and condensing solvent vapor arising from any ofthem, and thereby preventing its overflow from the apparatus andnormally supplying the overflowing well with purified liquid solvent; astorage reservoir for purifled solvent, and means for diverting thecondensed solvent into said storage reservoir, so that the contents ofsaid well receiving the overflow as aforesaid may be distilled down topermit 01' its being cleaned out while the excess of purified distillateis meanwhile held in said storage reservoir; and means for pumping upliquid solvent from either said overflowing well or said storagereservoir over into the other, well.

10. Apparatus of the character described, for treating things or worktherein with volatile solvent whose vapor is heavier than air,comprising an air-excluding treating vessel open upward for introductionand removal 01' work, and provided with means affording separate solventwells in said vessel, one higher than ana other and normally dischargingthereinto, each of said wells being adapted to receive the work, andalso provided with a storage reservoir under the higher well forreceiving liquid solvent there from, and with means above said wells forretaining and condensing solvent vapor evolved in the vessel and thuspreventing its overflow from the apparatus, and for thereby supplyingthe higher well with purified solvent, and means for the transfer ofliquid solvent from said storage reservoir to one of the wells.

11. Apparatus ot the character described, for treating things or worktherein with volatile solvent whose vapor is heavier than air,comprising an air-excluding treating vessel open upward for introductionand removal or work, and provided with means affording separate solventwells in said vessel, one higher than another and normally dischargingthereinto, each of said wells being adapted to receive the work, andalso provided with a storage reservoir under the higher well forreceiving liquid solvent therefrom, and with means above said wells forretaining and condensing solvent vapor evolved in the vessel and thuspreventing its' overflow from the apparatus, and for thereby supplyingthe higher well with purified solvent, and means for pumping up liquidsolvent from said storage reservoir over into said lower well.

12. Apparatus of the character described, for treating things or worktherein with volatile solvent whose vapor is heavier than air,comprising an air-excluding treating vessel open for introduction andremoval of work, and provided with means including a dam affordingseparate solvent wells in said vessel and providing for accumulation ofliquid solvent in one of said wells higher than the solvent level inanother and overflow of excess from the one well over said dam into theother, the top of said dam sloping gently upward, in the direction ofoverflow, to its crest, and also provided with means above said 'wellsfor condensing solvent vapor evolved in the vessel and thereby supplyingthe overflowing well with liquid solvent. H

' CLARENCE F. DINLEY.

